New York City residents would be able to identify themselves as belonging to more than one race on city documents under legislation that was to be introduced in the City Council on Tuesday.

“We just wanted to bring New York City into the 21st century,” explained Councilwoman Margaret Chin, a Manhattan Democrat who is the measure’s lead sponsor. “This will allow New Yorkers to identify their heritage and be proud of it. They shouldn’t have to only check one box.”

The city has the highest population of multiracial residents in the United States, with 325,901 individuals identifying as more than one race on the 2010 U.S. Census.

The bill, which is co-sponsored by Democratic Councilmen Ben Kallos and Corey Johnson, would require city agencies to ensure they have the capacity to maintain the new demographic information within three years of the bill’s enactment as law.